Unprecedented Hurricane Tomas pounding the Lesser Antilles

By: Dr. Jeff Masters , 3:38 PM GMT on October 30, 2010

Share this Blog
7
+

Hurricane Tomas, an unprecedented Lesser Antilles hurricane for so late in the season, is bearing down on the islands of St. Lucia and St. Vincent with Category 1 winds of 75 mph. Recent radar imagery from the Martinique radar shows that Tomas is still in the organizing stage, with an eyewall that just closed off, and a weak area of echoes on the south side, due to modest wind shear of 10 knots caused by southerly upper-level winds. The Hurricane Hunters reported top surface winds in the northern eyewall near 75 mph. St.Lucia figures to get the worst blow from Tomas, as this island will experience the strong right-front quadrant of the storm--the north eyewall. Winds on the island were sustained at 46 mph, gusting to 67 mph, at 11am EDT. Winds at Barbados peaked at 37 mph, gusting to 56 mph, early this morning, and the pressure bottomed out at 994 mb. Satellite loops of Tomas show a large and well-organized Cape Verdes-type hurricane, with good upper level outflow on all sides except the south, and an impressive amount of heavy thunderstorm activity. This is a very dangerous hurricane that is just beginning to get going. You can follow the progress of Tomas through the islands today with our wundermap zoomed in on St. Lucia.


Figure 1. Morning radar image from the Martinique radar shows the eye of Tomas moving between the islands of St, Lucia to the north and St. Vincent and the Grenadines to the south. The southern portion of the eyewall had just closed off with this image. Image credit: Meteo France.

Intensity forecast for Tomas
Now that the eyewall of Tomas has completely closed off, a period of steady and possibly rapid intensification lasting until Sunday afternoon is likely. The intensification rate may then be slowed by an increasing flow of southwesterly upper-level winds, which are expected to bring dry air and a moderate 15 - 20 knots of wind shear to Tomas Sunday through Tuesday, according to the latest SHIPS model forecast. Shear is then expected to relent, allowing more intensification on Wednesday. Water temperatures are a record warm 29.5°C and the Tropical Cyclone Heat Potential--a measure of the total heat content of the ocean--is a very high 100 kJ/cm^2, which is very favorable for rapid intensification. I expect the Tomas will strengthen to a Category 3 or 4 hurricane by Wednesday.


Figure 2. Hurricane specialists Robbie Berg (background) and Dan Brown (foreground) discuss the latest data on Tomas last night at the National Hurricane Center.

Track forecast for Tomas
The computer models have come into better agreement this morning that after Tomas reaches the central Caribbean 4 - 5 days from now, a turn to the north or northeast is likely, in response to a strong trough of low pressure expected to develop over the Eastern U.S. The exact timing of this turn to the north or northeast is difficult to predict at this time, as steering currents will be weak in the Caribbean after Tomas passes through the Lesser Antilles today and Sunday. At this time, is appears that the Dominican Republic and Haiti are most at risk from a strike by Tomas, though the storm could move as far west as Jamaica, or as far east as the northern Lesser Antilles Islands.


Figure 3. Hurricane specialist Dan Brown computes Tomas' radius of tropical storm force winds using the old-fashioned paper track plot and dividers technique. Hurricane specialists at NHC commonly use a paper track plot to mark all storm center fixes and compute the current motion of the storm. A storm's current heading and speed in NHC advisories is usually a 12-hour average of the motion up until the final fix position.

Tomas, Shary, and the 2010 hurricane season in perspective
Tomas' formation ties 2010 with 1995 and 1887 for 3rd place for most number of named storms in an Atlantic hurricane season. Only 2005 (28 named storms) and 1933 (21 named storms) were busier. Atlantic hurricane records go back to 1851, though there were likely many missed named storms prior to the beginning of satellite coverage in the mid-1960s. The intensification of Shary and Tomas into hurricanes today brings the total number of hurricanes this season to twelve, tying 2010 with 1969 and 1887 for second place for most hurricanes in a season. The record is held by 2005 with fifteen hurricanes, and I don't think we'll beat that record this year!

The formation of Tomas so far south and east this late in the season is unprecedented in the historical record; no named storm has ever been present east of the Lesser Antilles (61.5°W) and south of 12°N latitude so late in the year. Hurricane Six of 1896 came close--it was also a tropical storm south of 12°N and east of 61.5°W on October 29, but nine hours earlier in the day. That storm recurved to the north and missed the Lesser Antilles. Tomas' track through the southern Lesser Antilles so late in the year is unprecedented. There have been only two other tropical storms that formed after October 15 south of 12°N and east of 61.5°W: Hurricane Jose, which was a tropical storm in that region on October 18, 1999, and Tropical Storm Nicolas, on October 16, 2003. Tomas most reminds me of a storm I flew into with the Hurricane Hunters--Hurricane Joan of 1988, which was a tropical storm on October 14 near Tomas' current location, and later strengthened into a Category 4 hurricane that hit Nicaragua. According to Chenoweth (2008), Tomas is the first tropical storm to cross through the Lesser Antilles Islands south of 16°N this late in the year since 1724. In that year, a tropical storm on 12 November crossed the islands at 13.7°N 61.5°W, and later became a hurricane that affected Jamaica. There was also a hurricane on 30 October 1671 that crossed 61.5°W at 13.3°N, and did damage on Barbados.

Another unusual aspect of Tomas' formation is that we now have two simultaneous hurricanes in the Atlantic Ocean on October 30. There has been only one hurricane season since 1851 that had had two simultaneous hurricanes later in the year--1932, when Hurricane Ten and Hurricane Eleven both existed November 7 - 10. Today is also the 5th latest date in the season that there have been two simultaneous named storms in the Atlantic. The record was set way back in 1887, when Hurricane Eighteen and Tropical Storm Nineteen were both active on December 8. There were three years that had simultaneous November named storms: 1932, 1961, and 2001.

References
Chenoweth, M. and D. Divine (2008), "A document-based 318-year record of tropical cyclones in the Lesser Antilles, 1690-2007", Geochemistry, Geophysics, Geosystems, 9, doi:10.1029/2008GC002066.

Next update
I'll have more on Sunday by 3pm EDT. I'm headed home to Michigan today, after a very valuable week here at the National Hurricane Center. The experience gave me a new appreciatation for just how good the forecasters are at what they do. NHC's hurricane experts are truly world-class, and we are very fortunate to have such a talented group of hard-working forecasters keeping us informed on the dangers we face from Atlantic hurricanes.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 593 - 543

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35Blog Index

DON'T FORGET, THE DAYLIGHT SAVING TIME ENDS TONIGHT
Member Since: Posts: Comments:

Quoting hurricanehunter27:
This could be dean part 2. =(
Conditions are not favorable for it to reach anything close to Dean's intensity.
Member Since: Posts: Comments:
This could be dean part 2. =(
Member Since: Posts: Comments:

Member Since: Posts: Comments:
588. amd
Quoting Hurricanes101:


see post 570


officially yes.

Unofficially, the Hurricane Reanalysis Project thinks that the Hurricane that hit Cuba in November of 1932 was a cat 5.

Excerpt from: November 1932 Cuba Hurricane

While the storm is currently listed in the HURDAT as a marginal Category 4 hurricane on the Saffir-Simpson hurricane scale with no listed pressure,[3] according to the Hurricane Reanalysis Project the hurricane likely reached Category 5 intensity with 160 mph (260 km/h) winds when it made landfall in Cuba with a minimum central pressure of 915 mbar.[4] If that were determined to be correct, it would be the latest Category 5 hurricane ever recorded in the Atlantic basin, surpassing Hurricane Hattie of the 1961 season by six days. It would also easily be the strongest storm (and only Category 5 hurricane) ever recorded in the month of November, well ahead of Hurricane Lenny's 933 mbar pressure. In addition, such an upgrade would make the 1932 season the first of five seasons with multiple Category 5 hurricanes, joining the 1960, 1961, 2005 and 2007 seasons; additionally, this such upgrade would also make the 1932 season the first Atlantic hurricane season to have multiple Category 5 landfalls, an event only repeated by the 2007 season.
Member Since: Posts: Comments:
IS the NHC always conservative with the intensity of a TC? Is it because they would rather raise it later in the forecast than have to lower it?
Member Since: Posts: Comments:
Can someone link the 15 day models? I'm going to the Caribbean in 14 days...would like to see long term models idea of what is up, even with Tomas beyond 5 days.
Member Since: Posts: Comments:
this cant be good
Member Since: Posts: Comments:
THE POST-TROPICAL STORM IS RACING NORTHEASTWARD AT ABOUT 42 KT.

That's Wilma like speed! Zoom Zoom.
Member Since: Posts: Comments:
Quoting Dakster:
When was the latest a Cat 5 formed?

Tomas looking menacing now!

Hurricane Hattie in 1961.
Link
Member Since: Posts: Comments:
A very serious situation is developing in the Caribbean, hope everyone is prepared and ready! Please be safe!!
Member Since: Posts: Comments:
Quoting Dakster:
When was the latest a Cat 5 formed?

Tomas looking menacing now!


see post 570
Member Since: Posts: Comments:
00
WTNT45 KNHC 302034
TCDAT5
TROPICAL STORM SHARY DISCUSSION NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL202010
500 PM AST SAT OCT 30 2010

SATELLITE IMAGES INDICATE THAT A STRONG COLD FRONT IS NOW
INTERACTING WITH SHARY AND THE FSU CYCLONE PHASE SPACE DIAGRAMS
SUGGEST THAT CYCLONE HAS TRANSITIONED TO A POST-TROPICAL CYCLONE.
BASED ON THESE DATA...SHARY IS NO LONGER CONSIDERED A TROPICAL
CYCLONE AND THIS WILL BE THE LAST ADVISORY ISSUED ON THIS STORM
FROM THE NATIONAL HURRICANE CENTER.

THE POST-TROPICAL STORM IS RACING NORTHEASTWARD AT ABOUT 42 KT.
THIS MOTION IS EXPECTED TO CONTINUE UNTIL THE CYCLONE BECOMES
ABSORBED BY THE FRONT WITHIN THE NEXT 6 TO 12 HOURS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 30/2100Z 39.2N 50.9W 60 KT
12HR VT 31/0600Z 42.8N 44.2W 55 KT...DISSIPATED
24HR VT 31/1800Z...DISSIPATED



RIP on this storm
Member Since: Posts: Comments:
Still wondering about the Curacao call....odd.
Member Since: Posts: Comments:
Quoting SunnyDaysFla:
Hope you are wrong Taz, nobody needs a Cat 5. Where you been? have not seen your name here in a while.



my HP laptop crashed so am on one of my older ones
Member Since: Posts: Comments:
As bad as it is, St. Lucia dodged a bullet with Tomas not completing his eye wall structure until now(or soon...). It could have been worse...
Member Since: Posts: Comments:
Tomas looks on or just a touch south of the tropical points, anyone see this or is it just me?
Member Since: Posts: Comments:

Quoting Hurricanes101:


Hurricane Hattie holds that distinction having become a Category 5 hurricane on October 30th, 1961


Member Since: Posts: Comments:
Quoting AstroHurricane001:
6 PM special advisory brings Tomas to 95 kt and keeps it there between 48h and 96h. That seems an awfully long time to keep a hurricane at just 1 kt under major hurricane strength, and I think the NHC did that to make a conservative change to a forecast that came only 1 hour after the last full advisory. This basically means that we could have a cat. 3 as early as Monday, and strengthening is likely to follow that afterwards but may be somewhat inhibited by shear.

initial 30/2200z 13.5n 61.6w 80 kt
12hr VT 31/0600z 14.0n 63.4w 85 kt
24hr VT 31/1800z 14.5n 65.7w 90 kt
36hr VT 01/0600z 14.9n 67.9w 90 kt
48hr VT 01/1800z 15.2n 69.7w 95 kt
72hr VT 02/1800z 15.7n 72.4w 95 kt
96hr VT 03/1800z 16.0n 74.0w 95 kt
120hr VT 04/1800z 16.5n 74.5w 100 kt
we could see MAJOR HURRICANE STATUS by 6 pm sunday if not before
Member Since: July 15, 2006 Posts: 178 Comments: 56047
When was the latest a Cat 5 formed?

Tomas looking menacing now!
Member Since: Posts: Comments:
Quoting AstroHurricane001:
6 PM special advisory brings Tomas to 95 kt and keeps it there between 48h and 96h. That seems an awfully long time to keep a hurricane at just 1 kt under major hurricane strength, and I think the NHC did that to make a conservative change to a forecast that came only 1 hour after the last full advisory. This basically means that we could have a cat. 3 as early as Monday, and strengthening is likely to follow that afterwards but may be somewhat inhibited by shear.

initial 30/2200z 13.5n 61.6w 80 kt
12hr VT 31/0600z 14.0n 63.4w 85 kt
24hr VT 31/1800z 14.5n 65.7w 90 kt
36hr VT 01/0600z 14.9n 67.9w 90 kt
48hr VT 01/1800z 15.2n 69.7w 95 kt
72hr VT 02/1800z 15.7n 72.4w 95 kt
96hr VT 03/1800z 16.0n 74.0w 95 kt
120hr VT 04/1800z 16.5n 74.5w 100 kt


They do not change the forecast intensity or track unless its at the 5pm or 11pm advisories

they will likely change it at 11pm
Member Since: Posts: Comments:

Member Since: Posts: Comments:
Quoting weatherlover94:
unheard of if we get a cat 5 in late Oct early November


Hurricane Hattie holds that distinction having become a Category 5 hurricane on October 30th, 1961
Member Since: Posts: Comments:
6 PM special advisory brings Tomas to 95 kt and keeps it there between 48h and 96h. That seems an awfully long time to keep a hurricane at just 1 kt under major hurricane strength, and I think the NHC did that to make a conservative change to a forecast that came only 1 hour after the last full advisory. This basically means that we could have a cat. 3 as early as Monday, and strengthening is likely to follow that afterwards but may be somewhat inhibited by shear.

initial 30/2200z 13.5n 61.6w 80 kt
12hr VT 31/0600z 14.0n 63.4w 85 kt
24hr VT 31/1800z 14.5n 65.7w 90 kt
36hr VT 01/0600z 14.9n 67.9w 90 kt
48hr VT 01/1800z 15.2n 69.7w 95 kt
72hr VT 02/1800z 15.7n 72.4w 95 kt
96hr VT 03/1800z 16.0n 74.0w 95 kt
120hr VT 04/1800z 16.5n 74.5w 100 kt
Member Since: Posts: Comments:
Quoting alfabob:


Wow, Tomas is going to hit cat 2 before midnight EDT. Possibly cat 3 within 12-24 hours, and if he hits the orange with favorable conditions; cat 5.


I really hope not :/ what a crazy season this has been.....
Member Since: Posts: Comments:
Hope you are wrong Taz, nobody needs a Cat 5. Where you been? have not seen your name here in a while.
Member Since: Posts: Comments:
this has went from TS at 40 mph too 60 mph then 75 mph too now 90mph ouch can you say RI?
Member Since: Posts: Comments:
In reality, the winds are probably near 100mph.




Member Since: Posts: Comments:
Quoting SLU:


I made a correct call on the intensity or TOMAS. Way too much damage is being reported from St. Lucia for this to have been at only 75mph.

6:00 PM AST Sat Oct 30
Location: 13.5°N 61.6°W
Max sustained: 90 mph
Moving: WNW at 10 mph
Min pressure: 982 mb

It looks like RI could be on.
The NHC said they also thought it was stronger due to the damages being reported.
Member Since: Posts: Comments:
Quoting Saltydogbwi1:


I would much rather this comes our way than over Haiti only issue with that is Jamaica is between us and Tomas and they dont need any more bad weather either. Pretty difficult to wish a storm out of the carib without affecting someone though. ;-p

I think with Tomas most of the Caribbean Islands are stuck between a rock and hard place, anywhere it goes, most will feel something out of it, JMO.
Member Since: Posts: Comments:
RI/21L/H/T/C2
MARK
13.526n/61.88w


Member Since: July 15, 2006 Posts: 178 Comments: 56047
unheard of if we get a cat 5 in late Oct early November
Member Since: Posts: Comments:
some in tells me we may have a cat 5 out of this the way its going and am not likeing the way this is turning out
Member Since: Posts: Comments:
Eyewall 90% complete


Member Since: Posts: Comments:
Quoting Saltydogbwi1:


I would much rather this comes our way than over Haiti only issue with that is Jamaica is between us and Tomas and they dont need any more bad weather either. Pretty difficult to wish a storm out of the carib without affecting someone though. ;-p
Yep. They have had terrible flooding issues.
Member Since: Posts: Comments:
Odd, NHC issuing probabilities for Curacao, but not Aruba or Bonaire...

CURACAO 34 X 4( 4) 5( 9) 6(15) 5(20) 3(23) 3(26)
CURACAO 50 X X( X) 2( 2) 1( 3) 2( 5) X( 5) 2( 7)
CURACAO 64 X X( X) X( X) 1( 1) 1( 2) X( 2) 1( 3)

Member Since: Posts: Comments:
555. SLU
Quoting SLU:


It's the annual Creole Day Festival. It was actually supposed to take place tomorrow but it's been cancelled.

I just spoke to my brother in St. Lucia and he painted a picture of complete mayhem on the island. There is a powerful rain band moving across now and he said that those are the worst conditions he'd seen so far today.

I think the NHC's 75mph wind speed estimate is indeed too low based on what i'm hearing from St. Lucia. This is beginning to look more like a high-end cat 1 or even a low-end cat 2 hurricane.


I made a correct call on the intensity or TOMAS. Way too much damage is being reported from St. Lucia for this to have been at only 75mph.

6:00 PM AST Sat Oct 30
Location: 13.5°N 61.6°W
Max sustained: 90 mph
Moving: WNW at 10 mph
Min pressure: 982 mb

It looks like RI could be on.
Member Since: Posts: Comments:
554. JRRP
Member Since: August 16, 2007 Posts: 0 Comments: 6213
St. Lucia is getting pounded right now.

Surprised they were even able to get that report out to the NHC.
Member Since: Posts: Comments:
Quoting Hurricanes101:
UMMARY OF 600 PM AST...2200 UTC...INFORMATION
----------------------------------------------
LOCATION...13.5N 61.6W
ABOUT 45 MI...75 KM WSW OF ST. LUCIA
ABOUT 30 MI...50 KM WNW OF ST. VINCENT
MAXIMUM SUSTAINED WINDS...90 MPH...150 KM/HR
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 10 MPH...17 KM/HR
MINIMUM CENTRAL PRESSURE...982 MB...29.00 INCHES


Holy crap!
Member Since: Posts: Comments:
Quoting stormwatcherCI:
I know but still think by Tuesday should know whether we need to shutter up or not. In one way I hope not but then again for the sake of Haiti I would say I hope so. At least here we live in houses and don't have to expect to shelter in tents. I feel it for them and it's bad enough with a regular thunderstorm not to mention a potential major hurricane. More worried for my grand-daughter who is getting ready to start nursing school in Jamaica.


I would much rather this comes our way than over Haiti only issue with that is Jamaica is between us and Tomas and they dont need any more bad weather either. Pretty difficult to wish a storm out of the carib without affecting someone though. ;-p
Member Since: Posts: Comments:
Member Since: August 2, 2010 Posts: 21 Comments: 9882
Quoting Hurricanes101:
Winds up to 90mph


lets see at 8 pm then we could go into rapid intensification
Member Since: Posts: Comments:
UMMARY OF 600 PM AST...2200 UTC...INFORMATION
----------------------------------------------
LOCATION...13.5N 61.6W
ABOUT 45 MI...75 KM WSW OF ST. LUCIA
ABOUT 30 MI...50 KM WNW OF ST. VINCENT
MAXIMUM SUSTAINED WINDS...90 MPH...150 KM/HR
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 10 MPH...17 KM/HR
MINIMUM CENTRAL PRESSURE...982 MB...29.00 INCHES
Member Since: Posts: Comments:
Winds up to 90mph
Member Since: Posts: Comments:
Wow, up to 90mph based on observations out of St. Lucia.
Member Since: Posts: Comments:
Quoting Hurricanes101:


ok I have asked 3 times and no one responded, (not saying you did, you probably just got here)

when is recon scheduled to be back in Tomas? I thought it said 18Z which means it should be there now.
18Z is 2 pm EDT. Not sure if they were out there or not.
Member Since: Posts: Comments:
Quoting MarcoIslandCat5:
if tomas gets to 80w/85w would he carry on heading west or is the north east hook stil in play?? thanks
florida pete


there is so much model spread right now the hurricane center is showing only a slight northward jog by Wednesday then the north east curve will be in question if you live in Florida watch this one until it starts the ne hook
Member Since: Posts: Comments:

Viewing: 593 - 543

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Overcast
30 °F
Overcast

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron